Specification guide
AMS7280 O-Rings
AMS7280 fluorocarbon O-rings called out by AS3084 and AS3085: the document, how it relates to AMS7276 and the M83248 family, and which one to quote.
AMS7280 is an SAE Aerospace Material Specification for fluorocarbon (FPM type, the older European name for FKM) sealing rings: high-temperature fluid resistant, low compression set, 70 to 80 hardness. The part standards AS3084 and AS3085 call out this material, with dash numbers following the AS568 size system. It is the older of the two SAE fluorocarbon O-ring specifications still seen on drawings; AMS7276 is the current default, and Conquest's legacy compound chart listed one 75 A compound against both. This guide covers what the document is, the part numbers that carry it, how it relates to AMS7276 and the M83248 family, and what an RFQ needs to state.
What the document is
| Item | Value | Source |
|---|---|---|
| Full title (SAE) | Rings, sealing, synthetic rubber, high temperature fluid resistant, low compression set, FPM type, 70 to 80 | SAE Mobilus standard page for AMS7280 |
| Status | Revised; current revision AMS7280F (1992); originally issued 1970 | SAE document record, read September 2026 |
| Material | Fluorocarbon (FPM is the older designation for FKM) | Document title |
| Hardness | 70 to 80 (75 A nominal) | Document title |
| Part standards that invoke it | AS3084 (boss sizes, -YY), AS3085 (AS568 dash sizes, -XXX) | SAE part standard records; Conquest's legacy cross-reference chart |
| Qualified products list | None recorded for this document | SAE document record |
| Nearest current document | AMS7276 (active, revision J 2020, SAE-held QPL) | SAE document record |
The title carries no temperature; a specification is not an operating limit.
Part numbers and related callouts
| Part number form | Material specification | Hardness | Sizes | Note |
|---|---|---|---|---|
| AS3085-XXX | AMS7280 | 75 A | AS568 three-digit dash sizes | The standard O-ring sheet for this material |
| AS3084-YY | AMS7280 | 75 A | Two-digit boss-seal sizes | Straight-thread fitting seals |
| AS3209-XXX, AS3208-YY | AMS7276 | 75 A | Dash and boss sizes | The current default fluorocarbon callout; see the AMS7276 guide |
| M83248/1-XXX, AS83248/1-XXX | MIL-R-83248 Class 1, now AMS7276 | 75 A | Dash sizes | The military family; see the M83248 guide |
| AS3581-XXX | AMS7259 | 90 A | Dash sizes | The high-hardness companion |
| MS9387-YY | AMS7278 | 75 A | Boss sizes | Listed with AMS7276 and AMS7280 on Conquest's legacy chart as one compound family |
| 2-XXX (Parker®) and commercial FKM | none | 60 to 90 A | AS568 sizes | Same size system, no qualification; not a substitute without the print's permission |
What material is it, and what can it take?
Fluorocarbon (FKM) rubber, the family covered in the Viton® guide. The Parker O-Ring Handbook (ORD 5700) rates standard FKM compounds for continuous service from -26 C (-15 F) to 204 C (400 F), with low-temperature grades to -46 C (-51 F) and short excursions to 232 C; the qualified compound's own sheet governs. The service is the same as AMS7276: aircraft fuels and lubricants at high temperature, with low compression set so the seal keeps its force through long hot service. Where FKM fails (steam, ketones, amines, brake fluid) it fails under any of these documents; the chemical compatibility guide covers the media.
Why AMS7280 still appears on drawings
The document was first issued in 1970 and last revised in 1992, which puts it on the drawings of airframes, engines and ground equipment designed through the 1970s and 1980s and still flying or in service. Drawings are not redrawn when a newer material specification appears, so a maintenance order for a 1980s program calls for AS3085-XXX in AMS7280 material long after new designs moved to AMS7276. The part standards AS3084 and AS3085 carry the sizes, and the company's legacy cross-reference chart pairs both with the same 75 A fluorocarbon service description as AS3208 and AS3209: aircraft fuels and lubricants. What the title promises is the property set the family is known for, high-temperature fluid resistance with low compression set, so the seal keeps its force through long hot service in fuel and oil. What the title does not promise is an operating temperature; the Parker handbook's caution applies to every document in this family.
AMS7280 or AMS7276: which one to quote?
| What the drawing says | What to supply | Why |
|---|---|---|
| AS3085-XXX or AMS7280, no alternate | An AS3085 part in AMS7280 material from a qualified manufacturer | The print governs; the same compound is often qualified to both documents |
| AMS7280 "or equivalent" | AS3209 in AMS7276, with the cross-reference on the certificate | AMS7276 is the active document with an SAE-held QPL |
| M83248/1-XXX | AS83248/1 or AS3209 in AMS7276 | The MIL document was cancelled in favor of AMS7276 |
| 90 hardness or Class 2 | AS3581 in AMS7259 | AMS7280 and AMS7276 are 70 to 80 A documents |
| Fuel seal with cold-soak requirement | Ask about AMS7379 or AMS-R-83485 | Low-temperature fluorocarbon documents |
| Commercial equipment, no spec | A commercial 75 A FKM O-ring | No qualification needed; lower cost |
What should the RFQ state?
The part standard and dash number (AS3085-214), the quantity, whether AMS7276 material is an acceptable equivalent, the drawing revision if named, and the documentation required (certificate of conformance to the specification; the manufacturer's test report if the program requires it; lot traceability). State the quantity per size and the delivery destination, since qualified parts ship with paperwork per lot. The mil-spec O-ring chart lists the related documents and the AS568 chart the sizes.
How Conquest Seal supplies it
Parts to these documents are made by manufacturers on the relevant qualified products list, where the document has one; Conquest supplies them as a distributor and provides the certification paperwork (certificate of conformance naming the specification and, where the manufacturer issues one, the test report). Conquest's quality management system handles the order and the paperwork; it is not a product qualification and is unrelated to any QPL. See aerospace and defense sealing.
Viton is a trademark of The Chemours Company; Parker is a trademark of Parker Hannifin Corporation. No affiliation or endorsement is implied.
Sources
- Parker O-Ring Handbook ORD 5700, section 2.2, read 2026-09-14
- AMS-R-83485
- AMS7259
- AMS7276
- AMS7278
- AMS7280
- AMS7379
- AS3084
- AS3085
- AS3208
- AS3209
- AS3581
- AS568
- AS83248
- MIL-R-83248
- SAE Mobilus
- SAE and DLA ASSIST document records for the specifications named, read September 2026
Reviewed by Grant Midstokke, Conquest Seal Corporation. Last updated September 2026. Spec values in this guide are drawn from the sources named in the sentence where each appears; the compound datasheet and your application conditions govern the final choice.
Frequently asked questions
Is AMS7280 obsolete?
The document stands at revision F from 1992 and is still cited on drawings; AMS7276 is the active document most new drawings use. Supply what the print names unless it allows the equivalent.
What does FPM mean in the title?
The older ISO-style designation for fluorocarbon rubber; FKM is the ASTM D1418 designation for the same family.
What is the difference between AS3084 and AS3085?
Sizes. On the company's legacy cross-reference chart AS3084 carries the two-digit boss-seal sizes and AS3085 the three-digit AS568 dash sizes, both in AMS7280 material.
Can one compound be qualified to both AMS7280 and AMS7276?
Yes; Conquest's legacy compound chart listed one 75 A fluorocarbon compound against AMS-R-83248, AMS7276, AMS7278 and AMS7280 together. The certificate names the document you ordered to.
What temperature is it good for?
The document is a materials and test specification. For the FKM family the Parker handbook range is -26 C to 204 C continuous; the qualified compound's sheet and the application govern.
Does the dash number on an AS3085 part match the AS568 chart?
Yes. AS3085-214 is the AS568-214 size in AMS7280 material; the two-digit AS3084 numbers are the boss-seal sizes. The dash number guide explains both series, and a print that mixes the two is asking for two different seals.
What is the current revision of AMS7280?
The SAE record shows revision F, dated 1992, which is why it reads as an older document next to AMS7276. It is still an active specification, and the part standards AS3084 and AS3085 that call it out are themselves current at revision A of 2012.
What hardness does AMS7280 material carry?
70 to 80 Shore A, the same band as AMS7276. Conquest's legacy compound chart listed one 75 A fluorocarbon compound against both documents and against the cancelled MIL-R-83248, which is the practical reason the two specifications are often quoted together.
Is a certificate required with an AMS7280 order?
Yes. A certificate of conformance ships with every order, naming the part number, the specification, the manufacturer, the lot and the quantity; the manufacturer's batch test report can be requested where the program requires it. Qualification belongs to the compound maker, never to the distributor that stocks the part.
Related guides
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